Loss of p16Ink4a with retention of p19Arf predisposes mice to tumorigenesis.

The cyclin-dependent kinase inhibitor p16INK4a can induce senescence of human cells, and its loss by deletion, mutation or epigenetic silencing is among the most frequently observed molecular lesions in human cancer. Overlapping reading frames in the INK4A/ARF gene encode p16INK4a and a distinct tumour-suppressor protein, p19ARF (ref. 3). Here we describe the generation and characterization of a p16Ink4a-specific knockout mouse that retains normal p19Arf function. Mice lacking p16Ink4a were born with the expected mendelian distribution and exhibited normal development except for thymic hyperplasia. T cells deficient in p16Ink4a exhibited enhanced mitogenic responsiveness, consistent with the established role of p16Ink4a in constraining cellular proliferation. In contrast to mouse embryo fibroblasts (MEFs) deficient in p19Arf (ref. 4), p16Ink4a-null MEFs possessed normal growth characteristics and remained susceptible to Ras-induced senescence. Compared with wild-type MEFs, p16Ink4a-null MEFs exhibited an increased rate of immortalization, although this rate was less than that observed previously for cells null for Ink4a/Arf, p19Arf or p53 (refs 4, 5). Furthermore, p16Ink4a deficiency was associated with an increased incidence of spontaneous and carcinogen-induced cancers. These data establish that p16Ink4a, along with p19Arf, functions as a tumour suppressor in mice.     

Cloning and functional research of renal cell carcinoma related novel gene—— GYLZ-RCC18

After the renal cell carcinoma related novel gene fragmentGYLZ-RCC18 was cloned by using suppression subtractive hybridization (SSH), we used the SMART RACE technology to clone the full length ofGYLZ-RCC18 and performed chromosome location by the FISH method. RT-PCR was used to detect the expression of the first reading frame ofGYLZ-RCC18 in different stages and grades of renal cell carcinoma tissue and other tissues. Also we transfected the antisense oligonucleotide ofGYLZ-RCC18 to renal cell carcinoma cell line GRC-1, and analyzed the proliferation activity, growth speed, apoptosis and mortality changes in GRC-1. The results show that the full length ofGYLZ-RCC18 (GenBank accession No.: BE825133) cDNA is about 3.5 kb long which is located at No. 14 chromosome.GYLZ-RCC18 has a higher expression in higher grades and stages of renal cell carcinoma than in the lower ones. The expression ofGYLZ-RCC18 in renal cell carcinoma was much higher than that in normal kidney and other tissues. After transfection ofGYLZ-RCC18 antisense oligonucleotide, the mortality of GRC-1 increases evidently, the proliferation activity and growth speed were inhibited remarkably at the same time. Also the antisense oligonucleotide can induce the apoptosis of GRC-1 all through the observation time. Our results indicated thatGYLZ-RCC18 is an important novel gene related to renal cell carcinoma. Its overexpression would stimulate the growth and proliferation activity and plays an antidead and antiapoptosis effect in renal cell carcinoma. Transfection of antisense oligonucleotide could inhibit the generation and development of renal cell carcinoma. The study provides a new clue for the research of renal cell carcinoma, and also provides an instruction for special genetic diagnosis and the therapy of renal cell carcinoma.     

内蒙古草地挥发性有机物的预研究

内蒙古草原挥发性有机物的研究在大气化学、大气环境领域具有重要的作用。2001年夏季,利用便携式光离子化检测器以及采样仪器对于内蒙古草原的一些优势草种进行了测量,得到了对内蒙古草原挥发性有机物的初步认识。     

An integration model for manpower forecasting

Manpower forecasting has made significant contributions to human resource management. Due to difficulties in collecting the required data for making appropriate analysis, most studies in the literature concentrate on forecasts of individual firms. This paper presents a regression model which utilizes the data of large firms to draw inferences to the demands of other firms. More specifically, a regression model showing the negative relationship between the rank of a firm and its associated demand is fitted to the data of a number of large manufacturing firms. The area under the regression line delineated by the y-axis is then an estimate of the total demand of the whole industry. Confidence intervals for the estimate can also be constructed. As an illustration, the demand for the industrial management manpower in Taiwan is forecasted by applying the proposed model.     

多功能化纳米材料络合物体外特异性结合和调控结肠癌细胞的研究

 循环肿瘤细胞(CTCs)因携带原发肿瘤的一些生物特性以及自身独特的生物学功能,在癌症的诊断、治疗和转移预防方面发挥着重要作用.但外周血中CTCs 的低含量使其检测、分离和富集有一定技术难度.本文选取结肠癌HT29 细胞为CTCs 模型,以表面高表达的EpCAM 为生物标记物,选取纳米级高分子聚合物G6 PAMAM dendrimers 为基质,多价络合针对EpCAM的抗体来构建络合物,实现体外对HT29 细胞的特异性捕获及活性调控.应用红外、动态光散射、紫外和荧光等方法表征络合物的理化特性,荧光分析法考察络合物对HT29 细胞的识别和捕获,MTT、荧光拍照、流式分析法显示络合物对捕获的HT29 细胞的活性调控.结果表明,制备的络合物可以高特异性地识别和结合贴壁的和悬浮的HT29 细胞,从而对捕获的细胞产生一定的活性下调作用,但不产生严重的细胞毒效应.可见,利用具有多价络合效应的纳米材料来共价连接针对CTCs 表面标记物的靶向抗体,有望实现在病人血中对CTCs 的特异性捕获和活性调控.     

Interdependence of behavioural variability and response to small stimuli in bacteria

The chemotaxis signalling network in Escherichia coli that controls the locomotion of bacteria is a classic model system for signal transduction. This pathway modulates the behaviour of flagellar motors to propel bacteria towards sources of chemical attractants. Although this system relaxes to a steady state in response to environmental changes, the signalling events within the chemotaxis network are noisy and cause large temporal variations of the motor behaviour even in the absence of stimulus. That the same signalling network governs both behavioural variability and cellular response raises the question of whether these two traits are independent. Here, we experimentally establish a fluctuation-response relationship in the chemotaxis system of living bacteria. Using this relationship, we demonstrate the possibility of inferring the cellular response from the behavioural variability measured before stimulus. In monitoring the pre- and post-stimulus switching behaviour of individual bacterial motors, we found that variability scales linearly with the response time for different functioning states of the cell. This study highlights that the fundamental relationship between fluctuation and response is not constrained to physical systems at thermodynamic equilibrium but is extensible to living cells. Such a relationship not only implies that behavioural variability and cellular response can be coupled traits, but it also provides a general framework within which we can examine how the selection of a network design shapes this interdependence.     

黄灯期间信号交叉口的驾驶员行为

交叉口安全评价、信号方案设计等工作中必须考虑黄灯期间驾驶员的行为特性,为此需要构建合理的驾驶员行为模型。针对黄灯期间信号交叉口的驾驶员行为模型进行研究,利用视频采集驾驶员在黄灯期间的行为数据,经数据预处理后,考虑黄灯启亮时刻车辆位置、车速两个因素,运用Logistic回归构建了驾驶员行为模型,并利用受试者工作特征曲线(ROC曲线)等检验了模型的准确性。     

地下圆形衬砌洞室对SV及Rayleigh波的动应力集中(I):3-D级数解

为了研究地下圆形衬砌洞室在入射平面SV波和Rayleigh波作用下的动应力集中问题,利用波函数展开法,求解出三维条件下的级数解.当衬砌与半空间介质相同时,级数解将退化为无衬砌时的结果.级数解为进一步定量分析衬砌洞室对入射平面SV波和Rayleigh波的动力集中提供了理论基础.     

地下圆形衬砌洞室对SV及Rayleigh波的动应力集中(Ⅰ):3-D级数解

为了研究地下圆形衬砌洞室在入射平面SV波和Rayleigh波作用下的动应力集中问题,利用波函数展开法,求解出三维条件下的级数解。当衬砌与半空间介质相同时,级数解将退化为无衬砌时的结果。级数解为进一步定量分析衬砌洞室对入射平面SV波和Rayleigh波的动力集中提供了理论基础。